Hello. Thank you for your question. Welcome to HCM. I understand your concern. A normal kidney with normal function filter and excretes the dye in about two to three hours, it pools in the kidneys and goes out with urine. However, there are cases even with normal kidneys that the contrast agent acutely damages the kidney function and it takes up to three weeks of daily intravenous normal saline infusions, to get the creatinine levels within normal. Anyway, these cases do not happen often. There is a different story when a kidney is shut down, chronic renal failure is installed, and we have to do the angiogram. In our clinic s experience, we use a cut-off value of 1.6 for creatinine, in deciding whether to proceed with the angiogram or not, and we undertake all the measures to bring the figures to the above mentioned figure and then carry out the exam. Of course, this is the case for elective angiogram. In acute cases, where the maximum benefit is achieved within 6 hours from onset of chest pain to angioplasty and stent placement, the benefit is greater on the stent placement side, so, no matter how high is creatinine, the procedure is carried out. But, after the procedure, the patient should have a course of dialysis to clear the contrast dye from organism and to bring creatinine levels down to at least the primary levels, when admitted. I hope I was helpful with my answer. Best regards. Dr. Meriton